Merge pull request #196 from jimhall/gs-install-deps

Language added to confirm proper installation of ghostscript libraries

docs/user/install-deps.rst

@@ -3,72 +3,59 @@
 Installation of dependencies
 ============================
 
-The dependencies `Tkinter`_ and `ghostscript`_ can be installed using your system's package manager. You can run one of the following, based on your OS.
+The dependencies `Ghostscript <https://www.ghostscript.com>`_ and `Tkinter <https://wiki.python.org/moin/TkInter>`_ can be installed using your system's package manager or by running their installer.
-
-.. _Tkinter: https://wiki.python.org/moin/TkInter
-.. _ghostscript: https://www.ghostscript.com
 
 OS-specific instructions
 ------------------------
 
-For Ubuntu
+Ubuntu
-^^^^^^^^^^
+^^^^^^
 ::
 
-    $ apt install python-tk ghostscript
+    $ apt install ghostscript python3-tk
 
-Or for Python 3::
+MacOS
-
+^^^^^
-    $ apt install python3-tk ghostscript
-
-For macOS
-^^^^^^^^^
 ::
 
-    $ brew install tcl-tk ghostscript
+    $ brew install ghostscript tcl-tk
 
-For Windows
+Windows
-^^^^^^^^^^^
+^^^^^^^
 
-For Tkinter, you can download the `ActiveTcl Community Edition`_ from ActiveState. For ghostscript, you can get the installer at the `ghostscript downloads page`_.
+For Ghostscript, you can get the installer at their `downloads page <https://www.ghostscript.com/download/gsdnld.html>`_. And for Tkinter, you can download the `ActiveTcl Community Edition <https://www.activestate.com/activetcl/downloads>`_ from ActiveState.
 
-.. _ActiveTcl Community Edition: https://www.activestate.com/activetcl/downloads
+Checks to see if dependencies are installed correctly
-.. _ghostscript downloads page: https://www.ghostscript.com/download/gsdnld.html
+-----------------------------------------------------
-.. _as shown here: https://java.com/en/download/help/path.xml
 
-Checks to see if dependencies were installed correctly
+You can run the following checks to see if the dependencies were installed correctly.
-------------------------------------------------------
 
-You can do the following checks to see if the dependencies were installed correctly.
+For Ghostscript
+^^^^^^^^^^^^^^^
+
+Open the Python REPL and run the following:
+
+For Ubuntu/MacOS::
+
+    >>> from ctypes.util import find_library
+    >>> find_library("gs")
+    "libgs.so.9"
+
+For Windows::
+
+    >>> from ctypes.util import find_library
+    >>> find_library("".join(("gsdll", str(ctypes.sizeof(ctypes.c_voidp) * 8), ".dll"))
+    <name-of-ghostscript-library-on-windows>
+
+**Check:** The output of the ``find_library`` function should not be empty.
+
+If the output is empty, then it's possible that the Ghostscript library is not available one of the ``LD_LIBRARY_PATH``/``DYLD_LIBRARY_PATH``/``PATH`` variables depending on your operating system. In this case, you may have to modify one of those path variables.
 
 For Tkinter
 ^^^^^^^^^^^
 
-Launch Python, and then at the prompt, type::
+Launch Python and then import Tkinter::
-
-    >>> import Tkinter
-
-Or in Python 3::
 
     >>> import tkinter
 
-If you have Tkinter, Python will not print an error message, and if not, you will see an ``ImportError``.
+**Check:** Importing ``tkinter`` should not raise an import error.
-
-For ghostscript
-^^^^^^^^^^^^^^^
-
-Run the following to check the ghostscript version.
-
-For Ubuntu/macOS::
-
-    $ gs -version
-
-For Windows::
-
-    C:\> gswin64c.exe -version
-
-Or for Windows 32-bit::
-
-    C:\> gswin32c.exe -version
-
-If you have ghostscript, you should see the ghostscript version and copyright information.

docs/user/install.rst

@@ -5,42 +5,35 @@ Installation of Camelot
 
 This part of the documentation covers the steps to install Camelot.
 
-Using conda
+After :ref:`installing the dependencies <install_deps>`, which include `Ghostscript <https://www.ghostscript.com>`_ and `Tkinter <https://wiki.python.org/moin/TkInter>`_, you can use one of the following methods to install Camelot:
------------
 
-The easiest way to install Camelot is to install it with `conda`_, which is a package manager and environment management system for the `Anaconda`_ distribution.
+.. warning:: The ``lattice`` flavor will fail to run if Ghostscript is not installed. You may run into errors as shown in `issue #193 <https://github.com/camelot-dev/camelot/issues/193>`_.
-::
 
-    $ conda install -c conda-forge camelot-py
+pip
+---
 
-.. note:: Camelot is available for Python 2.7, 3.5, 3.6 and 3.7 on Linux, macOS and Windows. For Windows, you will need to install ghostscript which you can get from their `downloads page`_.
+To install Camelot from PyPI using ``pip``, please include the extra ``cv`` requirement as shown::
-
-.. _conda: https://conda.io/docs/
-.. _Anaconda: http://docs.continuum.io/anaconda/
-.. _downloads page: https://www.ghostscript.com/download/gsdnld.html
-.. _conda-forge: https://conda-forge.org/
-
-Using pip
----------
-
-After :ref:`installing the dependencies <install_deps>`, which include `Tkinter`_ and `ghostscript`_, you can simply use pip to install Camelot::
 
     $ pip install "camelot-py[cv]"
 
-.. _Tkinter: https://wiki.python.org/moin/TkInter
+conda
-.. _ghostscript: https://www.ghostscript.com
+-----
+
+`conda`_ is a package manager and environment management system for the `Anaconda <https://anaconda.org>`_ distribution. It can be used to install Camelot from the ``conda-forge`` channel::
+
+    $ conda install -c conda-forge camelot-py
 
 From the source code
 --------------------
 
-After :ref:`installing the dependencies <install_deps>`, you can install from the source by:
+After :ref:`installing the dependencies <install_deps>`, you can install Camelot from source by:
 
 1. Cloning the GitHub repository.
 ::
 
     $ git clone https://www.github.com/camelot-dev/camelot
 
-2. Then simply using pip again.
+2. And then simply using pip again.
 ::
 
     $ cd camelot